You have a chance to suggest a name for one of Mercury’s impact craters!

The MESSENGER science team has selected five craters of particular geological interest for this contest. The International Astronomical Union (IAU) is the global authority in charge of assigning official names to features on the planets. According to the IAU rules for Mercury, impact craters are named in honor of people who have made outstanding or fundamental contributions to the Arts and Humanities (visual artists, writers, poets, dancers, architects, musicians, composers and so on). The person must have been recognized as an art-historically significant figure for more than 50 years and must have been dead for at least three years. We are particularly interested in submissions that honor people from nations and cultural groups that are under-represented amongst the currently-named craters. See the current list of named Mercury craters.

While it will never power our cars here on Earth, I find it fantastic that the Mercury-bound MESSENGER spacecraft is sailing the solar wind to avoid using fuel for course corrections. Even better, solar wind was originally seen as a liability to the mission and now has been turned into a helpful tool.

Fuel saved now opens up more options once MESSENGER reaches orbit in 2011.

Like this:

When the first several days worth of Mercury pictures from the Messenger probe were released from JPL, I had to admit to a little disappoint. Mercury seemed rather moonlike, even the part we hadn’t seen yet.

“MESSENGER has shown that Mercury is even more different from the Moon than we’d thought,” said Science Team Co-Investigator James Head, professor at Brown University and chair of the mission’s Geology Discipline Group. The tiny spacecraft discovered a unique feature that the scientists dubbed, “The Spider.” This type of formation has never been seen on Mercury before, and nothing like it has been observed on the Moon. It is in the middle of the Caloris basin and consists of over a hundred narrow, flat-floored troughs (called graben) radiating from a complex central region. “The Spider” has a crater near its center, but whether that crater is related to the original formation or came later is not clear at this time.

The whole report is worth reading. Patience in science is a good thing. I ought to try it.

Like this:

In my last posting on the MESSENGER mission, I said that the probe would be photographing parts of Mercury we hadn’t seen before. Here is one of the first pictures from such areas from a January 15, 2008 press release:

Why hadn’t we been able to take pictures of this side of Mercury before? The research team explains in their press release:

When Mariner 10 flew past Mercury three times in 1974 and 1975, the same hemisphere was in sunlight during each encounter. As a consequence, Mariner 10 was able to image less than half the planet. Planetary scientists have wondered for more than 30 years about what spacecraft images might reveal about the hemisphere of Mercury that Mariner 10 never viewed.

So, how does this hemisphere compare to what we’ve seen before? Again, the research team:

Like the previously mapped portion of Mercury, this hemisphere appears heavily cratered. It also reveals some unique and distinctive features. On the upper right is the giant Caloris basin, including its western portions never before seen by spacecraft. Formed by the impact of a large asteroid or comet, Caloris is one of the largest, and perhaps one of the youngest, basins in the Solar System. The new image shows the complete basin interior and reveals that it is brighter than the surrounding regions and may therefore have a different composition. Darker smooth plains completely surround Caloris, and many unusual dark-rimmed craters are observed inside the basin. Several other multi-ringed basins are seen in this image for the first time. Prominent fault scarps (large ridges) lace the newly viewed region.

The Mercury Flyby Visualization Tool will offer simulated views of what Messenger will see during its approach, flyby and departure from the closest planet to the sun. The site will offer real-time simulations as the spacecraft rendezvous with the planet Jan. 14. Johns Hopkins University’s Applied Physics Laboratory is hosting the service.

The tool will use the best low-resolution imagery and surface maps of Mercury generated on Earth, from such sources as the Arecibo Observatory in Puerto Rico and image mosaics from the Mariner 10 spacecraft Mercury flybys. This imagery will be augmented with material generated on the Messenger by spectrometer and laser altimeter.

Much more information about NASA’s Messenger mission can be found by visiting http://messenger.jhuapl.edu. The January 14th flyby is one of the steps that NASA expects to lead toward Messenger being the first probe to actually orbit Mercury in 2014.

One thing that amazed me when I went to the Messenger site was realizing how FAST the probe is moving. On January 11th, Messenger was about 1.1 million miles away from Mercury. At this distance, Mercury appears as a tiny crescent as shown in this photograph:

By flyby time on January 14th, the probe will be 124 miles above the planet, which is about the same distance as many spy satellites. Just think, a million miles in a little under three days. For perspective, that’s roughly three times faster than it took Apollo astronauts to make it to the moon, which is a quarter of that distance.

Why have the real thing if we got images enough for a simulation? Because 1) Messenger will photograph large areas of the planet missed by earlier probes and inaccessible to earth telescopes and 2) much higher resolution will be available.